Transmitter, receiver, transmitting method, receiving method, variable-length serial burst data transfer system, semiconductor device and hybrid semiconductor device

ABSTRACT

A transmitter for use in a variable-length serial burst data transfer system having the transmitter and a receiver that are connected by at least two data transmission lines and a burst start line includes a two-line encoder and a burst start signal receiving portion. During transmitting variable-length serial transmit data made up of binary digits, the two-line encoder encodes the transmit data into transmit data symbols that are each associated with each piece of transmit data in advance, inserts an identification symbol for identifying the transmit data symbols from one another between the transmit data symbols resulting from encoding to encode the transmit data, and transmits the encoded transmit data via the two data transmission lines to the receiver. During non-transmit, the two-line encoder transmits a non-transmit symbol representing a non-transmit state via the two data transmission lines to the receiver. The burst start signal receiving portion receives a burst start signal, which represents start of burst transmission of the variable-length serial transmit data, via the burst start line from the receiver. In the transmitter, the two-line encoder transmits the identification symbol to the receiver at the start of the burst transmission, and performs the burst transmission of the variable-length serial transmit data in response to the burst request signal receiving portion receiving the burst start signal from the receiver in accordance with the transmitted identification symbol.

The entire disclosure of Japanese Patent Application No. 2007-123357,filed May 8, 2007 is expressly incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Technical Field

An aspect of the present invention relates to an asynchronous datatransfer.

More particularly, the invention relates to a communication system forimplementing a signaling method that performs a variable-length serialburst data transfer at high speed in communication using two-phase tofour-phase handshaking.

2. Related Art

A data transfer between asynchronous systems is performed by means oftwo-phase to four-phase handshaking.

As such a technique, the technique is known that is disclosed in DesignWave Magazine, July, 2005, pp. 64-91, Case studies on “asynchronousprocessors”, Complete cure for noise and power consumption problems withdigital LSI, by Nobuo Karaki.

However, the two-phase to four-phase handshaking disclosed in the abovearticle has a problem in that handshaking by bit in transferring serialdata blocks causes overhead, requiring a long transfer time.

Accordingly, there is another problem in that high-speed serial datatransfer cannot be achieved by an asynchronous data transfer methodusing two-phase to four-phase handshaking.

SUMMARY

An advantage of the present invention is to provide a communicationsystem that allows high-speed serial data transfer by an asynchronousdata transfer method using two-phase to four-phase handshaking.

A transmitter according to a first aspect of the invention is one foruse in a variable-length serial burst data transfer system having thetransmitter and a receiver that are connected by at least two datatransmission lines and a burst start line.

The transmitter includes a two-line encoder and a burst start signalreceiving portion.

During transmitting variable-length serial transmit data made up ofbinary digits, the transmitter encodes the transmit data into transmitdata symbols that are each associated with each piece of transmit datain advance, inserts an identification symbol for identifying thetransmit data symbols from one another between the transmit data symbolsresulting from encoding to encode the transmit data, and transmits theencoded transmit data via the two data transmission lines to thereceiver.

During non-transmit, the transmitter transmits a non-transmit symbolrepresenting a non-transmit state via the two data transmission lines tothe receiver.

The burst start signal receiving portion receives a burst start signal,which represents start of burst transmission of the variable-lengthserial transmit data, via the burst start line from the receiver.

The two-line encoder transmits the identification symbol to the receiverat the start of the burst transmission, and performs the bursttransmission of the variable-length serial transmit data in response tothe burst request signal receiving portion receiving the burst startsignal from the receiver in accordance with the transmittedidentification symbol.

According to the first aspect of the invention, effects are obtainedsuch that overhead caused in handshaking in asynchronous communicationcan be suppressed in asynchronous communication, in which communicationis started in response to a request for start of communication from thetransmitter; between the transmitter and the receiver, and that thestrength against environmental variations is achieved and high-speedcommunication at low power consumption is enabled because of theasynchronous communication.

A transmitter according to a second aspect of the invention is one foruse in a variable-length serial burst data transfer system having thetransmitter and a receiver that are connected by at least two datatransmission lines and a burst request line.

The transmitter includes a burst request signal receiving portion thatreceives a burst request signal via the burst request line from thereceiver, and a two-line encoder.

The burst request signal is a signal representing a request for bursttransmission of variable-length serial transmit data.

Responding to the burst request signal receiving portion receiving theburst start signal, during transmitting variable-length serial transmitdata made up of binary digits, the two-line encoder encodes the transmitdata into transmit data symbols that are each associated with each pieceof transmit data in advance, inserts an identification symbol foridentifying the transmit data symbols from one another between thetransmit data symbols resulting from encoding to encode the transmitdata, and transmits the encoded transmit data via the two datatransmission lines to the receiver.

During non-transmit, the two-line encoder transmits a non-transmitsymbol representing a non-transmit state via the two data transmissionlines to the receiver.

According to the second aspect of the invention, effects are obtainedsuch that overhead caused in handshaking in asynchronous communicationcan be suppressed in asynchronous communication, in which communicationis started in response to a request for start of communication from thetransmitter, between the transmitter and the receiver, and that thestrength against environmental variations is achieved and high-speedcommunication at low power consumption is enabled because of theasynchronous communication.

A receiver according to a third aspect of the invention is one for usein a variable-length serial burst data transfer system having atransmitter and the receiver that are connected by at least two datatransmission lines and a burst start line.

The receiver includes a storage, a two-line decoder, a data invalidsignal generator, a burst start signal generator and a burst startsignal transmitting portion.

The storage has received data stored therein and outputs a data emptysignal if being free of data stored.

The two-line decoder receives variable-length serial transmit data fromthe transmitter.

The variable-length serial transmit data is such that, duringtransmitting the variable-length serial transmit data made up of binarydigits, the transmit data is encoded into transmit data symbols that areeach associated with each piece of transmit data in advance, anidentification symbol for identifying the transmit data symbols from oneanother is inserted between the transmit data symbols resulting fromencoding to encode the transmit data, and the encoded transmit data istransmitted via the two data transmission lines to the receiver,although during non-transmit, a non-transmit symbol representing anon-transmit state is transmitted via the two data transmission lines tothe receiver.

The two-line decoder also outputs an identification symbol signal if theidentification symbol included in the received variable-length serialtransmit data is decoded and outputs a non-transmit symbol signal if thenon-transmit symbol included in the received variable-length serialtransmit data is decoded, and decodes the transmit data symbolsresulting from encoding based on the identification symbol included inthe received variable-length serial transmit data and stores the decodedtransmit data symbols as the received data in the storage.

The non-transmit symbol signal and the identification symbol signal areinput from the two-line decoder to the data invalid signal generator,and the data invalid signal generator generates a data invalid signalfrom input of the non-transmit symbol signal to input of theidentification symbol signal.

The data invalid signal represents that the received data is free frombeing stored into the storage.

The data invalid signal and the data empty signal are input to the burststart signal generator, and the burst start signal generator generates aburst start signal if both the data invalid signal and the data emptysignal are input.

The burst start signal is a signal representing start of the bursttransmission of the variable-length serial transmit data.

The burst start signal transmitting portion transmits to the transmitterthe burst start signal generated by the burst start signal generator.

A receiver according to a fourth aspect of the invention is one for usein a variable-length serial burst data transfer system having atransmitter and the receiver that are connected by at least two datatransmission lines and a burst request line.

The receiver includes a storage, a burst request signal transmittingportion, a two-line decoder, a data invalid signal generator and a burstend signal generator.

The storage has received data stored therein and outputs a data emptysignal if being free of data stored.

The burst request signal transmitting portion transmits a burst requestsignal via the burst request line to the transmitter.

The burst request signal is a signal that represents a request for bursttransmission of variable-length serial transmit data.

Responding to the transmitter receiving the burst request signal, thetwo-line decoder receives variable-length serial transmit data from thetransmitter.

The variable-length serial transmit data is such that, duringtransmitting the variable-length serial transmit data made up of binarydigits, the transmit data is encoded into transmit data symbols that areeach associated with each piece of transmit data in advance, anidentification symbol for identifying the transmit data symbols from oneanother is inserted between the transmit data symbols resulting fromencoding to encode the transmit data, and the encoded transmit datatransmitted via the two data transmission lines to the receiver,although during non-transmit, a non-transmit symbol representing anon-transmit state is transmitted via the two data transmission lines tothe receiver.

The two-line decoder also outputs an identification symbol signal if theidentification symbol included in the received variable-length serialtransmit data is decoded and outputs a non-transmit symbol signal if thenon-transmit symbol included in the received variable-length serialtransmit data is decoded, and decodes the transmit data symbolsresulting from encoding based on the identification symbol included inthe received variable-length serial transmit data and stores the decodedtransmit data symbols as the received data in the storage.

The non-transmit symbol signal and the identification symbol signal areinput from the two-line decoder to the data invalid signal generator,and the data invalid signal generator generates a data invalid signalfrom input of the non-transmit symbol signal to input of theidentification symbol signal.

The data invalid signal represents that the received data is free frombeing stored into the storage.

The data invalid signal and the data empty signal are input to a burstend signal generator, and the burst end signal generator generates andoutputs a burst start signal if both the data invalid signal and thedata empty signal are input.

The burst end signal represents end of receiving the variable-lengthserial transmit data.

In the receiver according to the third aspect of the invention, thetwo-line decoder may output the received data to the storage andtransmit, during output of the received data to the storage, a writesignal to the storage to cause the received data to be stored into thestorage.

The receiver may include a strobe signal generator to which the writesignal output by the two-line decoder is input and that outputs theinput write signal to the storage.

The strobe signal generator may mask the write signal, responding to thedata invalid signal being input from the data invalid signal generator.

According to this aspect of the invention, effects are obtained suchthat if a hazard occurs in received data to be received by the receiver,the receiver can receive the received data without being affected by thehazard.

In the receiver according to the third aspect of the invention, thetwo-line decoder outputs the received data, and the transmitter includesa serial-parallel converter that converts the received data outputparallel by the two-line decoder by a predetermined number of bits andcauses the received data converted parallel to be stored into thestorage.

According to this aspect of the invention, effects are obtained suchthat serial data received by the receiver can be stored as paralleldata.

A transmitting method according to a fifth aspect of the invention isone of a transmitter for use in a variable-length serial burst datatransfer system having the transmitter and a receiver that are connectedby at least two data transmission lines and a burst start line.

The transmitting method includes, during transmitting variable-lengthserial transmit data made up of binary digits, encoding the transmitdata into transmit data symbols, the transmit data symbols eachassociated with each piece of transmit data in advance, inserting anidentification symbol for identifying the transmit data symbols from oneanother between the transmit data symbols resulting from encoding toencode the transmit data, and transmitting the encoded transmit data viathe two data transmission lines to the receiver, and duringnon-transmit, transmitting a non-transmit symbol representing anon-transmit state via the two data transmission lines to the receiver;receiving a burst start signal via the burst start line from thereceiver, the burst start signal representing start of bursttransmission of the variable-length serial transmit data; andtransmitting the identification symbol to the receiver at the start ofthe burst transmission, and performing the burst transmission of thevariable-length serial transmit data in response to the burst requestsignal receiving portion receiving the burst start signal from thereceiver in accordance with the transmitted identification symbol.

A transmitting method according to a sixth aspect of the invention isone of a transmitter for use in a variable-length serial burst datatransfer system having the transmitter and a receiver that are connectedby at least two data transmission lines and a burst request line.

The transmitting method includes receiving a burst request signal viathe burst request line from the receiver, the burst request signal beinga signal that represents a request for burst transmission ofvariable-length serial transmit data; and in response to the burstrequest signal receiving portion receiving the burst start signal,during transmitting variable-length serial transmit data made up ofbinary digits, encoding the transmit data into transmit data symbols,the transmit data symbols each associated with each piece of transmitdata in advance, inserting an identification symbol for identifying thetransmit data symbols from one another between the transmit data symbolsresulting from encoding to encode the transmit data, and transmittingthe encoded transmit data via the two data transmission lines to thereceiver, and during non-transmit, transmitting a non-transmit symbolrepresenting a non-transmit state via the two data transmission lines tothe receiver.

A receiving method according to a seventh aspect of the invention is oneof a receiver for use in a variable-length serial burst data transfersystem having a transmitter and the receiver that are connected by atleast two data transmission lines and a burst start line.

The receiving method includes receiving variable-length serial transmitdata from the transmitter, the variable-length serial transmit databeing such that, during transmitting the variable-length serial transmitdata made up of binary digits, the transmit data is encoded intotransmit data symbols that are each associated with each piece oftransmit data in advance, an identification symbol for identifying thetransmit data symbols from one another is inserted between the transmitdata symbols resulting from encoding to encode the transmit data, andthe encoded transmit data transmitted via the two data transmissionlines to the receiver, although during non-transmit, a non-transmitsymbol representing a non-transmit state is transmitted via the two datatransmission lines to the receiver, outputting an identification symbolsignal if the identification symbol included in the receivedvariable-length serial transmit data is decoded and outputting anon-transmit symbol signal if the non-transmit symbol included in thereceived variable-length serial transmit data is decoded, and decodingthe transmit data symbols resulting from encoding based on theidentification symbol included in the received variable-length serialtransmit data and storing the decoded transmit data symbols as thereceived data in a storage; outputting a data empty signal if thestorage is free of data stored therein; receiving input of thenon-transmit symbol signal and the identification symbol signal, andgenerating a data invalid signal from input of the non-transmit symbolsignal to input of the identification symbol signal, the data invalidsignal representing that the received data is free from being storedinto the storage; receiving input of the data invalid signal and thedata empty signal, and generating a burst start signal if both the datainvalid signal and the data empty signal are input; and transmitting thegenerated burst start signal to the transmitter.

A receiving method according to an eighth aspect of the invention is oneof a receiver for use in a variable-length serial burst data transfersystem having a transmitter and the receiver that are connected by atleast two data transmission lines and a burst request line.

The receiving method includes transmitting a burst request signal viathe burst request line to the transmitter, the burst request signalbeing a signal that represents a request for burst transmission ofvariable-length serial transmit data; receiving, in response to thetransmitter receiving the burst request signal, variable-length serialtransmit data from the transmitter, the variable-length serial transmitdata being such that, during transmitting the variable-length serialtransmit data made up of binary digits, the transmit data is encodedinto transmit data symbols that are each associated with each piece oftransmit data in advance, an identification symbol for identifying thetransmit data symbols from one another is inserted between the transmitdata symbols resulting from encoding to encode the transmit data, andthe encoded transmit data is transmitted via the two data transmissionlines to the receiver, although during non-transmit, a non-transmitsymbol representing a non-transmit state is transmitted via the two datatransmission lines to the receiver, outputting an identification symbolsignal if the identification symbol included in the receivedvariable-length serial transmit data is decoded and outputting anon-transmit symbol signal if the non-transmit symbol included in thereceived variable-length serial transmit data is decoded, and decodingthe transmit data symbols resulting from encoding based on theidentification symbol included in the received variable-length serialtransmit data and storing the decoded transmit data symbols as thereceived data in the storage; outputting a data empty signal if thestorage being free of data stored therein; receiving input of thenon-transmit symbol signal and the identification symbol signal, andgenerating a data invalid signal from input of the non-transmit symbolsignal to input of the identification symbol signal, the data invalidsignal representing that the received data is free from being storedinto the storage; and receiving input of the data invalid signal thedata empty signal, and generating and outputting a burst start signal ifboth the data invalid signal and the data empty signal are input, theburst end signal representing end of receiving the variable-lengthserial transmit data.

In the receiving method according to the seventh aspect of theinvention, the receiver outputs the received data to the storage andtransmits, during output of the received data to the storage, a writesignal to the storage to cause the received data to be stored into thestorage, and masks the write signal in response to the data invalidsignal being input.

In the receiving method according to the seventh aspect of theinvention, the receiver converts the received data parallel by apredetermined number of bits and causes the received data convertedparallel to be stored into the storage.

A variable-length serial burst data transfer system according to a ninthaspect of the invention includes a transmitter and a receiver that areconnected by at least two data transmission lines and a burst startline.

The transmitter includes a two-line encoder and a burst start signalreceiving portion.

The two-line encoder, during transmitting variable-length serialtransmit data made up of binary digits, encodes the transmit data intotransmit data symbols, the transmit data symbols each associated witheach piece of transmit data in advance, inserts an identification symbolfor identifying the transmit data symbols from one another between thetransmit data symbols resulting from encoding to encode the transmitdata, and transmits the encoded transmit data via the two datatransmission lines to the receiver, and during non-transmit, transmits anon-transmit symbol representing a non-transmit state via the two datatransmission lines to the receiver.

The burst start signal receiving portion receives a burst start signalvia the burst start line from the receiver, the burst start signal beinga signal that represents start of burst transmission of thevariable-length serial transmit data.

In this case, the two-line encoder transmits the identification symbolto the receiver at the start of the burst transmission, and performs theburst transmission of the variable-length serial transmit data inresponse to the burst request signal receiving portion receiving theburst start signal from the receiver in accordance with the transmittedidentification symbol.

The receiver includes a storage, a two-line decoder, a data invalidsignal generator, a burst start signal generator and a burst startsignal transmitting portion.

The storage has received data stored therein and outputs a data emptysignal if being free of data stored.

The two-line decoder receives the encoded variable-length serialtransmit data from the transmitter, outputs an identification symbolsignal if the identification symbol included in the receivedvariable-length serial transmit data is decoded and outputs anon-transmit symbol signal if the non-transmit symbol included in thereceived variable-length serial transmit data is decoded, and decodesthe transmit data symbols resulting from encoding based on theidentification symbol included in the received variable-length serialtransmit data and stores the decoded transmit data symbols as thereceived data in the storage.

The non-transmit symbol signal and the identification symbol signal areinput from the two-line decoder to the data invalid signal generator,and the data invalid signal generator generates a data invalid signalfrom input of the non-transmit symbol signal to input of theidentification symbol signal, the data invalid signal representing thatthe received data is free from being stored into the storage.

The data invalid signal and the data empty signal are input to the burststart signal generator, and the burst start signal generator generates aburst start signal if both the data invalid signal and the data emptysignal are input.

The burst start signal transmitting portion transmits to the transmitterthe burst start signal generated by the burst start signal generator.

A variable-length serial burst data transfer system according to a tenthaspect of the invention includes a transmitter and a receiver that areconnected by at least two data transmission lines and a burst requestline.

The receiver includes a burst request signal transmitting portion thattransmits a burst request signal via the burst request line to thetransmitter, the burst request signal being a signal that represents arequest for burst transmission of variable-length serial transmit data.

The transmitter includes a burst request signal receiving portion and atwo-line encoder.

The burst request signal receiving portion receives the burst requestsignal via the burst request line from the receiver.

Responding to the burst request signal receiving portion receiving theburst start signal, during transmitting variable-length serial transmitdata made up of binary digits, the two-line encoder encodes the transmitdata into transmit data symbols, the transmit data symbols eachassociated with each piece of transmit data in advance, inserts anidentification symbol for identifying the transmit data symbols from oneanother between the transmit data symbols resulting from encoding toencode the transmit data, and transmits the encoded transmit data viathe two data transmission lines to the receiver, and duringnon-transmit, the two-line encoder transmits a non-transmit symbolrepresenting a non-transmit state via the two data transmission lines tothe receiver.

The receiver includes a storage, a two-line decoder, a data invalidsignal generator and a burst end signal generator.

The storage has received data stored therein and outputs a data emptysignal if being free of data stored.

The two-line decoder receives the encoded variable-length serialtransmit data from the transmitter, outputs an identification symbolsignal if the identification symbol included in the receivedvariable-length serial transmit data is decoded and outputs anon-transmit symbol signal if the non-transmit symbol included in thereceived variable-length serial transmit data is decoded, and decodesthe transmit data symbols resulting from encoding based on theidentification symbol included in the received variable-length serialtransmit data and stores the decoded transmit data symbols as thereceived data in the storage.

The non-transmit symbol signal and the identification symbol signal areinput from the two-line decoder to the data invalid signal generator,and the data invalid signal generator generates a data invalid signalfrom input of the non-transmit symbol signal to input of theidentification symbol signal, the data invalid signal representing thatthe received data is free from being stored into the storage.

The data invalid signal and the data empty signal are input to the burstend signal generator, and the burst end signal generator generates andoutputs a burst start signal if both the data invalid signal and thedata empty signal are input, the burst end signal representing end ofreceiving the variable-length serial transmit data.

In the variable-length serial burst data transfer system according tothe ninth aspect of the invention the data transmission lines may beeach a metal line.

In the variable-length serial burst data transfer system according tothe ninth aspect of the invention, the data transmission lines may beeach an optical fiber; the two-line encoder may include a light emitterthat outputs a transmit symbol via the optical fiber, the transmitsymbol being a transmit data symbol, an identification symbol or anon-transmit symbol; and the two-line decoder may include a lightreceiver that receives the transmit symbol via the optical fiber.

According to this aspect of the invention, effects are obtained suchthat the high-speed serial data transfer system can performcommunication under the reduced influence of electromagnetic waves andthe like from the outside.

In the variable-length serial burst data transfer system according tothis aspect of the invention, the light emitter may modulate an opticaloutput with high frequency in accordance with the transmit symbol; andthe light receiver may receive high-frequency light modulated inaccordance with the transmit symbol and decodes the data.

A semiconductor device according to a eleventh aspect of the inventionhas the variable-length serial burst data transfer system according tothe ninth aspect of the invention formed on one silicon substrate.

According to this aspect of the invention, effects are obtained suchthat a circuit in the semiconductor device formed on one siliconsubstrate can perform communication by the high-speed serial datatransfer system.

A hybrid semiconductor device according to a twelfth aspect of theinvention has the variable-length serial burst data transfer systemaccording to the ninth aspect of the invention formed on a plurality ofdifferent silicon substrates.

According to this aspect of the invention, effects are obtained suchthat the circuit in one semiconductor device including different siliconsubstrates can perform communication by the high-speed serial datatransfer system.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a schematic block diagram showing the configuration of ahigh-speed serial data transfer system according a first embodiment ofthe invention.

FIG. 2 is a truth table of data transmitted between a transmitter and areceiver.

FIG. 3 is a schematic block diagram showing the configuration of atransmitter according to the first embodiment.

FIG. 4 is a schematic block diagram showing the configuration of areceiver according to the first embodiment.

FIG. 5 is a timing chart showing operations of the high-speed serialdata transfer system according to the first embodiment.

FIG. 6 is a schematic block diagram showing the configuration of areceiver according to a second embodiment.

FIG. 7 is a schematic block diagram showing the configuration of ahigh-speed serial data transfer system according to a third embodimentof the invention.

FIG. 8 is a schematic block diagram showing the configuration of atransmitter according to the third embodiment.

FIG. 9 is a schematic block diagram showing the configuration of thereceiver according to the third embodiment.

FIG. 10 is a timing chart showing operations of a high-speed serial datatransfer system according to the third embodiment.

FIG. 11 is a schematic block diagram showing the configuration of areceiver according to a fourth embodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS First Embodiment ActiveSend-Passive Receive

Embodiments of the invention will be described below with reference tothe accompanying drawings.

FIG. 1 is a schematic block diagram showing the configuration of ahigh-speed serial data transfer system (variable-length serial burstdata transfer system) according to the first embodiment of thisinvention.

The high-speed serial data transfer system according to this firstembodiment is in a configuration of active send-passive receive.

The term “active send-passive receive” as used herein refers to acommunication system in which a transmitter transmits a request forstart of communication to a receiver and the receiver starts receivingin response to the request for start of communication from thetransmitter.

This high-speed serial data transfer system is composed of a high-speedserial data transmitter 10 and a high-speed serial data receiver 20.

The high-speed serial data transmitter 10 and the high-speed serial datareceiver 20 are connected by two data transmission lines d0 and d1.

The high-speed serial data transmitter 10 and the high-speed serial datareceiver 20 are connected also by a burst start signal line burststart1.

Hereinafter, the “high-speed serial data transmitter 10” will bereferred to as the “transmitter 10”, and the “high-speed serial datareceiver 20” as the “receiver 20”, for ease of description.

For example, the data transmission line d0 and the data transmissionline d1 are each a metal line.

The burst start signal line burststart1 is also a metal line.

The transmitter 10 transmits and receives transmit data data1, a sendcontrol signal send, a burst stop signal burststop and a burst startsignal burststart2 via a transmitting bus 30.

The receiver 20 transmits and receives a read signal read, data data3, aread acknowledgement signal ack1 and a burst request signal burstreq viaa receiving bus 40.

Connected to the transmitting bus 30 is a transmitting bus masterincluding a central processing unit (CPU) that performs transmission anda transmitting circuit, and the transmitting bus master controls thetransmitter 10 to transmit data to the receiver 20.

Connected to the receiving bus 40 is a receiving bus master including aCPU that performs receiving and a receiving circuit, and the receivingbus master controls the receiver 20 to receive transmit data from thetransmitter 10.

Two-Line Encoding

Encoding on the two data transmission lines d0 and d1, which connect thetransmitter 10 with the receiver 20, will next be described.

Transmit data is encoded, e.g., by means of a combination of a highlevel and a low level and transmitted to the two data transmission linesd0 and d1.

Hereinafter, a “high level” will be represented as “H” or “1”, and a“low level” as “L” or “0”.

Symbols encoded on the two data transmission lines d0 and d1 aredetermined in advance between a transmitter and a receiver as shown inFIG. 2.

Here, a case where the data transmission line d0 is 1 and the datatransmission line d1 is 1 is represented as a symbol “Invalid”.

A case where the data transmission line d0 is 0 and the datatransmission line d1 is 0 is represented as a symbol “Null”.

A case where the data transmission line d0 is 1 and the datatransmission line d1 is 0 is represented as a symbol “0”.

A case where the data transmission line d0 is 0 and the datatransmission line d1 is 1 is represented as a symbol “1”.

The symbol “0” and the symbol “1” represent binary transmit data; thesymbol “0” corresponds to the transmit data 0, and the symbol “1”corresponds to the transmit data 1.

Hereinafter, a symbol “0” will be represented as a “symbol 0”, and asymbol “1” as a “symbol 1”, and also a symbol 0 or a symbol 1 will berepresented as a “transmit data symbol”.

Further, a symbol “Invalid” will be represented as a “symbol I”, and asymbol “Null” as a symbol N.

Hereinafter, encoding described above will be referred to “two-lineencoding”.

In the two-line encoding, transmit data that is 0 or 1 is encoded intosymbols 0 or symbols 1, which correspond to the transmit data.

Further, a symbol N is added to a position before the symbol 0 or symbol1 obtained by encoding.

The addition of the symbol N to the position before the obtained symbol0 or symbol 1 results in that the symbol N is inserted between thesymbols 0 or symbols 1.

The symbol N enables a break between the symbols 0 or symbols 1 to bedetected.

Configuration of Transmitter 10

With reference to FIG. 3, the configuration of the transmitter 10 willnext be described.

In the figure, parts corresponding to parts in FIG. 1 are designated bythe same reference numerals, and the description thereof will beomitted.

The transmitter 10 includes an encoder 100 and a burst start signalreceiving portion 101.

The encoder 100 starts burst transmission in response to the fact thatthe burst stop signal burststop at L is input from the transmitting bus30.

After the start of burst transmission, the send control signal send andthe transmit data data1 are input from the transmitting bus 30 to theencoder 100.

The encoder 100 encodes the input transmit data data1 on the basis onthe input send control signal send, and the encoded transmit data istransmitted via the two data transmission lines d0 and d1 to thereceiver 20.

For example, in this encoding of the encoder 100, if the burst stopsignal burststop is at H and the send control signal send is at L, datais encoded as the symbol I.

If the burst stop signal burststop is at L and the send control signalsend is at L, the encoder 100 encodes the data as the symbol N.

If the burst stop signal burststop is at L and the send control signalsend is at H, the encoder 100 encodes the transmit data data1 as thesymbol 0 if the data is data 0, but on the other hand, the encoder 100encodes the transmit data data1 as the symbol 1 if the data is data 1.

Namely, during periods of transmitting variable-length serial transmitdata that is made up of binary digits, the encoder 100 encodes transmitdata into transmit data symbols (symbols 0 or symbols 1) that are eachassociated with each piece of transmit data in advance, insertsidentification symbols (symbols N) for identifying transmit data symbolsfrom one another between the transmit data symbols resulting fromencoding to encode the transmit data, and then transmits the encodedtransmit data via the two data transmission lines to the receiver.

During periods of not transmitting the transmit data, a non-transmitsymbol (symbol I) representing such a non-transmit state is transmittedvia the two data transmission lines to the receiver.

A burst start signal that is at H on the burst start signal lineburststart1 is input from the receiver 20 via the burst start signalline burststart1 to the burst start signal receiving portion 101, andthe burst start signal receiving portion 101 outputs the signal as theburst start signal burststart2 to the transmitting bus 30.

Configuration of Receiver 20

With reference to FIG. 4, the configuration of the receiver 20 will nextbe described in detail.

In the figure, parts corresponding to parts in FIG. 1 are designated bythe same reference numerals, and the description thereof will beomitted.

The receiver 20 includes a decoder 200, a first-in first-out (FIFO) 201,a data invalid signal generator 202, a strobe signal generator 203, aburst start signal generator 204 and a burst start signal transmittingportion 205.

The decoder 200 decodes two-line encoded transmit data that is inputfrom the transmitter 10 via the data transmission line d0 and the datatransmission line d1, and outputs the received data in accordance withthe symbol 0 or symbol 1 of the decoded transmit data, as the receiveddata data2, to the FIFO 201.

The decoder 200 changes the level of a data receive signal receive to Hin response to the change of the decoded data from the symbol I orsymbol N to the symbol 0 or symbol 1, and outputs the signal to thestrobe signal generator 203.

The decoder 200 generates this data receive signal receive, e.g., by anEXOR circuit having one input terminal thereof connected to the datatransmission line d0 and the other input terminal thereof connected tothe data transmission line d1.

The decoder 200 decodes the two-line encoded transmit data that is inputfrom the transmitter 10 via the data transmission line d0 and the datatransmission line d1, and changes the level of a symbol I signal inv toH when the decoded transmit data is symbol I, whereas it changes thelevel to L when the decoded transmit data is not symbol I.

The decoder 200 outputs the symbol I signal inv via a symbol I signalline to the data invalid signal generator 202.

The decoder 200 generates the symbol I signal inv, e.g., by an ANDcircuit having one input terminal thereof connected to the datatransmission line d0 and the other input terminal thereof connected tothe data transmission line d1.

The decoder 200 decodes the two-line encoded transmit data that is inputfrom the transmitter 10 via the data transmission line d0 and the datatransmission line d1.

The decoder 200 changes the level of a symbol N signal null to H whenthe decoded transmit data is the symbol N, whereas it changes the levelto L when the decoded transmit data is not the symbol N.

The decoder 200 outputs the symbol N signal null via a symbol N signalline to the data invalid signal generator 202.

The decoder 200 generates the symbol N signal null, e.g., by a NORcircuit having one input terminal thereof connected to the datatransmission line d0 and the other input terminal thereof connected tothe data transmission line d1.

The symbol I signal inv and the symbol N signal null are input from thedecoder 200 to the data invalid signal generator 202, and the datainvalid signal generator 202 generates data invalid signals datadis at H(true) for a period from a time when the level of the input symbol Isignal inv becomes H (true) to a time when the level of the symbol Nsignal null becomes H (true).

The data invalid signal generator 202 outputs the generated data invalidsignal datadis to the strobe signal generator 203 and the burst startsignal generator 204.

Input to the strobe signal generator 203 are the data invalid signaldatadis from the data invalid signal generator 202 and the data receivesignal receive from the decoder 200.

Only when the input data invalid signal datadis is at L (false), theinput data receive signal receive is output as a strobe signal strobe tothe FIFO 201.

The strobe signal generator 203, by way of example, includes an invertercircuit 231 and an AND circuit 232.

Input to an input terminal of the inverter circuit 231 is a data invalidsignal datadis from the data invalid signal generator 202.

The data invalid signal datadis inversed by the inverter circuit 231 isinput to one input terminal of the AND circuit 232.

The data receive signal receive is input from the decoder 200 to theother input terminal of the AND circuit 232.

The strobe signal strobe output from an output terminal of the ANDcircuit 232 is input to the FIFO 201.

The received data data2 is input from the decoder 200 to the FIFO 201,and the FIFO 201 stores the input received data data2 in the insidethereof in response to the fact that the strobe signal strobe is inputfrom the data invalid signal generator 202.

For example, the FIFO 201 stores the received data data2 input from thedecoder 200 in the inside thereof in response to the fact that thestrobe signal strobe input from the data invalid signal generator 202 israised from L to H.

The FIFO 201 outputs data stored in the inside thereof as the data data3to the receiving bus 40 in the order of storing the data in response tothe fact that a read signal read is input from the receiving bus 40, andalso outputs the read acknowledgement signal ack1 at H when the datadata3 is output.

The FIFO 201 monitors data stored in the inside thereof, and outputs adata empty signal empty at H to the burst start signal generator 204when no data is stored.

The data invalid signal datadis is input from the data invalid signalgenerator 202 and the data empty signal empty is also input from theFIFO 201 to the burst start signal generator 204.

When the input data invalid signal datadis is at H (true) and the inputdata empty signal empty is at H (true), the burst start signal generator204 generates a burst start signal such that a burst start signalburststart0 is at H (true), and outputs the generated burst start signalto the burst start signal transmitting portion 205.

The burst start signal generator 204 also outputs the burst start signalburststart0 as burst request signal burstreq to the receiving bus 40.

The burst start signal transmitting portion 205 transmits the inputburst start signal burststart0 via the burst start signal lineburststart1 to the transmitter 10.

Operations of Transmitter 10 and Receiver 20

With reference to FIG. 5, operations of the transmitter 10 and thereceiver 20 will next be described.

Here, a case where the transmitter 10 performs burst transmission of twopieces of transmit data, data 0 and data 1, will next be described.

Note that hereinafter description on time will be given assuming thattime t(i)<time t (i+1), where i is any natural number.

At a time t100 before burst communication, the encoder 100 of thetransmitter 10 transmits the symbol I via the two data transmissionlines d0 and d1 to the receiver 20.

Next, at a time t101, the burst stop signal burststop at L is input tothe encoder 100 of the transmitter 10 from the transmitting bus 30.

At a time t 102, 0 is input as the value of the transmit data data1 fromthe transmitting bus 30.

In response to the fact that the burst stop signal burststop at L isinput from the transmitting bus 30 at the time t101, the encoder 100 ofthe transmitter 10 transmits the symbol N via the two data transmissionlines d0 and d1 to the receiver 20 at and after a time t103

Here, in the symbol I, the level of data on the data transmission lined0 and the level of data on the data transmission line d1 are H, and inthe symbol N, the level of data on the data transmission line d0 and thelevel of data on the data transmission line d1 are L.

Accordingly, if a change is made from the symbol I to the symbol N, thelevels of data of the data transmission line d0 and the datatransmission line d1 are to be simultaneously changed from H to L.

However, due to a difference in wiring length between circuits, adifference in delay time of an element for performing transmission, andthe like, the data transmission line d0 and the data transmission lined1 may differ from each other in time taken for a change from H to L.

Therefore, if a change is made from the symbol I to the symbol N, ahazard may occur.

The description herein will be given assuming that the level of data ofthe data transmission line d1 changes from H to L at the time t101 andthe level of data of the data transmission line d0 changes from H to Lat the time t103, so that the transmit data is represented as the symbol0 in a period from the time t101 to the time t103.

This symbol 0 in the period from the time t101 to the time t103 is ahazard.

In general, the transmit data can be represented as the symbol 0 or thesymbol 1 in the period from the time t101 to the time t103, and thusthis symbol 0 is indefinite.

At the time t101, the decoder 200 of the receiver 20 that has receivedthe symbol 0 being indefinite changes the level of the symbol I signalinv to L and the level of the data receive signal receive to H inresponse to receiving the symbol 0, and outputs data 0 as the receiveddata data2.

In addition, at this time t101, although the decoder 200 of the receiver20 changes the level of the data receive signal receive to H because thedata invalid signal datadis that the data invalid signal generator 202of the receiver 20 outputs is at H, the strobe signal strobe that thestrobe signal generator 203 of the receiver 20 outputs is maintained tobe at L.

Therefore, data is not written into the FIFO 201 of the receiver 20.

That is, the strobe signal generator 203 of the receiver 20 can mask asignal at H of the data receive signal receive output by the decoder 200of the receiver 20 in response to received data, which is indefinite,caused by a hazard with the data invalid signal datadis output by thedata invalid signal generator 202 of the receiver 20.

Next, at the time t103, in response to receiving the symbol N, thedecoder 200 of the receiver 20 changes the level of the symbol N signalnull to H and the level of the data receive signals receive to L.

Also, at the time t103, in response to the change of the level of thesymbol N signal null to H, the data invalid signal generator 202 of thereceiver 20 changes the level of the data invalid signal datadis to L.

At the time t103, in response to the fact that the data invalid signalgenerator 202 of the receiver 20 outputs the data invalid signal datadisat L, the burst start signal generator 204 of the receiver 20 changesthe level of a signal on the burst start signal line burststart1 to Land transmits the burst start signal to the transmitter 10, and changesthe level of the burst request signal burstreq to L and outputs thesignal to the receiving bus 40.

At the time t103, when receiving the signal at L on the burst startsignal line burststart1 from the receiver 20, the burst start signalreceiving portion 101 of the transmitter 10 outputs the received signalat L on the burst start signal line burststart1 as the burst startsignal burststart2 to the transmitting bus 30.

Then, the receiving bus master connected to the transmitting bus 30starts burst transmission in response to receiving the burst startsignal.

Next, at a time t104, the send control signal send at H is input from atransmitting bus master of the transmitting bus 30 to the encoder 100 ofthe transmitter 10.

At the time t104, the encoder 100 of the transmitter 10 outputs thesymbol 0 to the receiver 20 in response to the input of the send controlsignal send at H.

At the time t104, the decoder 200 of the receiver 20 receives the symbol0.

At the time t104, in response to receiving the symbol 0, the decoder 200of the receiver 20 changes the level of the symbol N signal null to Land the level of the data receive signals receive to H, and outputs data0 as the received data data2.

Also, at the time t104, since the data invalid signal datadis that thedata invalid signal generator 202 of the receiver 20 outputs is at L,the strobe signal generator 203 changes the level of the strobe signalstrobe to H in response to the fact that the level of the data receivesignals receive is changed to H.

Also, at the time t104, in response to the change of the level of thestrobe signal strobe to H, the FIFO 201 stores the data 0 input as thereceived data data2 and changes the level of the data empty signal emptyto L.

Next, at a time t105, when the send control signal send at L is inputfrom the transmitting bus master of the transmitting bus 30 to theencoder 100 of the transmitter 10, the encoder 100 of the transmitter 10outputs the symbol N to the receiver 20.

Also, at the time t105, the decoder 200 of the receiver 20 receives thesymbol N, and changes the level of the symbol N signal null to H, andthe level of the data receive signal receive to L, in response toreceiving the symbol N.

Next, at a time t106, the transmit data 1 is input from the transmittingbus master of the transmitting bus 30 to the encoder 100 of thetransmitter 10 and, at a time t107, the send control signal send at H isinput from the transmitting bus master of the transmitting bus 30 to theencoder 100 of the transmitter 10.

The encoder 100 of the transmitter 10 outputs the symbol 1 to thereceiver 20 at this time t107 in response to the input of the sendcontrol signal send at H.

The decoder 200 of the receiver 20 causes the FIFO 201 to store the data1 input as the received data data2 at the time t107 in response toreceiving the symbol 1 in the same way as operations at the time t104.

In addition, at the time t107, in response to burst transmission of twopieces of transmit data, the burst stop signals burststop at the H levelare input from a transmitting bus master of the transmitting bus 30 tothe encoder 100 of the transmitter 10.

Next, at a time t108, the send control signal send at L is input fromthe transmitting bus master of the transmitting bus 30 to the encoder100 of the transmitter 10.

At the time t108, the send control signal send at L is input, and theencoder 100 of the transmitter 10 outputs the symbol I to the receiver20 because the input burst stop signal burststop is at H.

At the time t108, the decoder 200 of the receiver 20 receives the symbolI.

At the time t108, the decoder 200 of the receiver 20 changes the levelof the symbol I signal inv to H, and the level of the data receivesignal receive to L, in response to receiving the symbol I.

Here, in response to the fact that the burst start signal generator 204of the receiver 20 outputs the burst request signal burstreq to thereceiving bus 40 at the time t103, the receiving bus master connected tothe receiving bus 40 reads data from the FIFO 201 of the receiver 20 oneby one in the order in which the data is written into the FIFO 201 ofthe receiver 20 at and after the time t103.

The description herein is given assuming that all the data stored in theFIFO 201 of the receiver 20 has read by the receiving bus master at atime t109.

At the time t109, the FIFO 201 of the receiver 20 outputs the data emptysignal empty at H.

At the time t109, in response to the fact that the data empty signalempty at H is input from the FIFO 201 of the receiver 20, the burststart signal generator 204 of the receiver 20 transmits a signal at H onthe burst start signal line burststart1 to the transmitter 10, and theburst request signal burstreq at H to the receiving bus 40.

Receipt of the signal at H on the burst start signal line burststart1from the receiver 20 allows the transmitter 10 and the transmitting busmaster to detect that the transmit data transmitted by bursttransmission is normally received in the receiver 20.

The input of the burst request signal burstreq at H allows the receivingbus master to detect that all the received data from the bursttransmission has been read.

Note that regarding the transmitter 10 and the receiver 20 at the timeof starting the burst transmission, the encoder 100 transmits the symbolN to the receiver 20 at the start of the burst transmission.

In response to the fact that the burst start signal receiving portion101 receives the burst start signal burststart1 from the receiver 20 inresponse to the transmitted symbol N, variable-length serial transmitdata is burst transmitted to the receiver 20.

Second Embodiment Serial-Parallel Conversion Added to First Embodiment

Next, referring to FIG. 6, the configuration of a receiver 21 of ahigh-speed serial data transfer system according to the secondembodiment of the invention will be described.

In the figure, parts corresponding to parts in FIG. 4 are designated bythe same reference numerals, and the description thereof will beomitted.

In the high-speed serial data transfer system according to the firstembodiment, the receiver 20 stores serial data and serially outputs thestored serial data to the receiving bus 40.

As different from the high-speed serial data transfer system accordingto the first embodiment, a high-speed serial data transfer systemaccording to the second embodiment allows a receiver 21 corresponding tothe receiver 20 to store parallel data and to output the stored paralleldata in parallel to the receiving bus 40.

In the receiver 21 according to the second embodiment in FIG. 6, theFIFO 201, which is in the receiver 20 according to the first embodimentin FIG. 4, is changed to a FIFO 221.

The FIFO 201 of the first embodiment successively stores 1-bit data andsuccessively outputs 1-bit data.

On the other hand, the FIFO 221 of the second embodiment successivelystores data by a predetermined number of bits and successively outputsdata by a predetermined number of bits.

That is, the FIFO 201 stores serial data and outputs serial data.

On the other hand, the FIFO 221 stores parallel data and outputsparallel data.

Note that the data data3 that the FIFO 201 outputs is changed to datadata5 that the FIFO 221 outputs.

The data data3 is serial data, and data data5 is parallel data of nbits.

In the receiver 21 according to the second embodiment in FIG. 8, aserial-parallel converter 220 is added to between the decoder 200 andthe FIFO 201 in the receiver 20 according to the first embodiment inFIG. 5.

The serial-parallel converter 220 converts the serial data data2 decodedby the decoder 200 by a predetermined number of bits (n bits) toparallel data data4, and outputs the data4 that has been changed toparallel data.

For example, input to the serial-parallel converter 220 are the serialdata data2 from the decoder 200 and the strobe signal strobe from thestrobe signal generator 203.

In response to the input of the strobe signal strobe, theserial-parallel converter 220 converts the serial data data2 input by apredetermined number of bits to the parallel data data4, and outputs thedata4 converted to the parallel data to the FIFO 221.

The serial-parallel converter 220 outputs the strobe signal strobe by apredetermined number of bits to the FIFO 221 in response to the input ofthe strobe signal strobe.

The parallel data data4 and the strobe signal strobe are input from theserial-parallel converter 220 to the FIFO 221.

In response to the strobe signal strobe, the parallel data data4 isstored inside the FIFO 221.

In response to the input of the read signal read from the receiving bus40, the FIFO 201 outputs data stored in the inside thereof as theparallel data data5 of a predetermined number of bits in the order ofstoring the data to the receiving bus 40.

Other components and their operations in the second embodiment are thesame as those in the first embodiment, and the description thereof isomitted.

As described above, in the high-speed serial data transfer systemaccording to the second embodiment, as compared to the high-speed serialdata transfer system according to the first embodiment, the receiveddata can be stored by the serial-parallel converter 220 and the FIFO221.

With the high-speed serial data transfer system according to the secondembodiment, data stored in parallel can be output by a predeterminednumber of bits to the receiving bus 40 or the receiving bus masterconnected thereto.

Third Embodiment Passive Send-Active Receive

FIG. 7 is a schematic block diagram showing the configuration of ahigh-speed serial data transfer system according to the third embodimentof this invention.

While the first embodiment is a high-speed serial data transfer systemin a case of active send-passive receive, this third embodiment is ahigh-speed serial data transfer system in a case of passive send-activereceive.

In the figure, parts corresponding to parts in FIG. 1 are designated bythe same reference numerals, and the description thereof will beomitted.

While the transmitter 10 and the receiver 20 of FIG. 1 is connected bythe burst start signal line burststart1, the transmitter 15 and thereceiver 25 of FIG. 7 are connected by a burst request signal lineburstreq2.

While the burst start signal burststart2 is transmitted and receivedbetween the transmitter 10 and the transmitting bus 30 of FIG. 1, aburst request signal burstreq3 is transmitted and received between thetransmitter 15 and the transmitting bus 30 of FIG. 7.

While the burst request signal burstreq is transmitted and receivedbetween the receiver 20 and the receiving bus 40 of FIG. 1, a burst endsignal burstend is transmitted and received between the receiver 25 andthe receiving bus 40 of FIG. 7

Further, a burst request signal burstreq1 is transmitted and receivedbetween the receiver 25 and the receiving bus 40 of FIG. 7.

In the high-speed serial data transfer system according to the firstembodiment of FIG. 1, the transmitter 10 transmits a request signal viathe data transmission line d0 and the data transmission line d1 to thereceiver 20, and in response to the fact that the receiver 20 receives arequest signal, the receiver 20 changes the level of a signal of theburst start signal line burststart1 to H and outputs the single as anacknowledgement signal ack to the transmitter 10.

That is, in the first embodiment, the transmitter 10 startscommunication.

On the other hand, in the high-speed serial data transfer systemaccording to the third embodiment of FIG. 7, in response to the input ofthe burst request signal burstreq1 from the receiving bus 40 to thereceiver 25, the receiver 25 changes the level of the burst requestsignal line burstreq2 to H and transmits the burst request signal to thetransmitter 15.

Then, in response to receiving the burst request signal, which is at Hon the burst request signal line burstreq2, the transmitter 15 transmitsan acknowledgement signal ack via the data transmission line d0 and thedata transmission line d1 to the receiver 25.

Note that the content of this acknowledgement signal ack is that thesymbol transmitted via the data transmission line d0 and the datatransmission line d1 is one being not the symbol I, namely, the symbol 0or the symbol 1, or the symbol N.

Accordingly, the transmit data to be burst transmitted is included inthe acknowledgement signal ack.

As described above, in the high-speed serial data transfer systemaccording to the third embodiment, the receiver 25 starts communication.

Referring to FIG. 8, the configuration of the transmitter 15 will nextbe described. In the figure, parts corresponding to parts in FIGS. 7 and3 are designated by the same reference numerals, and the descriptionthereof will be omitted.

In FIG. 8, the burst start signal receiving portion 101 of FIG. 3 isreplaced by a burst request signal receiving portion.

The burst request signal receiving portion receives the burst requestsignal, which is at H on the burst request signal line burstreq2, viathe burst request signal line burstreq2 from the receiver 25.

The burst request signal receiving portion outputs the received burstrequest signal as the burst request signal burstreq3 to the transmittingbus 30.

The transmitting bus master connected to the transmitting bus 30receives the burst request signal burstreq3 via the transmitting bus 30to start burst transmission.

The burst request signal receiving portion 110 of FIG. 8 replacing theburst start signal receiving portion 101 of FIG. 3 perform the sameoperations as those of the burst start signal receiving portion 101 ofFIG. 3 except for the burst request signal line burstreq2 in place ofthe burst start signal line burststart1 and the burst request signalburstreq3 in place of the burst start signal burststart2.

Therefore, the description on other operations will be omitted.

Referring to FIG. 9, the configuration of the receiver 25 will next bedescribed. In the figure, parts corresponding to parts in FIGS. 7 and 4are designated by the same reference numerals, and the descriptionthereof will be omitted.

A burst end signal generator 214 of FIG. 9 generates the burst endsignal burstend in the same way as the burst start signal generator 204of FIG. 4 generates the burst request signal burstreq and outputs thesignal to the receiving bus 40.

Other components and operations of the burst end signal generator 214 ofFIG. 9 are the same as those of the burst start signal generator 204 ofFIG. 4, and therefore the description thereof will be omitted.

The burst request signal transmitting portion 210 of FIG. 9 transmitsthe burst request signal burstreq1 to the transmitter 10 via the burstrequest signal line burstreq2 in the same way as the burst start signaltransmitting portion 205 of FIG. 4 transmits the burst start signalsburststart0 to the transmitter 10 via the burst start line burststart1.

Other components and operations of the burst request signal transmittingportion 210 of FIG. 9 are the same as those of the burst start signaltransmitting portion 205 of FIG. 4, and therefore the descriptionthereof will be omitted.

However, there is a difference in that while the burst start signalburststart0 of FIG. 4 is generated by the burst start signal generator204 of FIG. 4, the burst request signal burstreq1 of FIG. 9 is output bythe receiving bus master via the receiving bus 40.

Referring to FIG. 10, the operations of the transmitter 15 and thereceiver 25 according to the third embodiment will next be described.

Only the different operations of the transmitter 15 and the receiver 25of FIG. 10 from those of the transmitter 10 and the receiver 20 of FIG.5 will be described.

First, a first difference is described.

At the time t101, the burst request signal transmitting portion 210 ofthe receiver 25 changes the level of a burst request signal on the burstrequest signal line burstreq2 to H and transmits the signal to thetransmitter 15.

At the time t101, the transmitter 15 transmits the burst request signalto the transmitting bus master.

Then, in response to receiving the burst request signal, thetransmitting bus master changes the burst stop signal burststop to L atthe time t101.

Then, a second difference is described.

At the time t103, in response to the change of the level of the burstend signal burstend to L, the receiving bus master changes the burstrequest signal to L, and at the time t103, the burst request signaltransmitting portion 210 of the receiver 25 changes the level of asignal on the burst request signal line burstreq2 to L.

Other components and their operations in the third embodiment are thesame as those in the first embodiment, and the description thereof isomitted.

Fourth Embodiment Serial-Parallel Conversion Added to Third Embodiment

Referring to FIG. 11, the configuration of a receiver 26 of a high-speedserial data transfer system according to the fourth embodiment of theinvention will next be described.

In the figure, parts corresponding to parts in FIG. 9 or 6 aredesignated by the same reference numerals, and the description thereofwill be omitted.

Similarly to the receiver 21 according to the second embodiment of FIG.6 with respect to the receiver 20 according to the first embodiment ofFIG. 4, the serial-parallel converter 220 in the receiver 26 accordingto the fourth embodiment is added to between the decoder 200 and theFIFO 201 in the receiver 2 according to the third embodiment of FIG. 9.

Similarly in the receiver 26 according to the fourth embodiment of FIG.11, the FIFO 221 replaces the FIFO 201 in the receiver 25 according tothe third embodiment of FIG. 9.

Accordingly, as different from the high-speed serial data transfersystem according to the third embodiment, in the high-speed serial datatransfer system according to the fourth embodiment, data can be outputin parallel by a predetermined number of bits to the receiving bus 40 orthe receiving bus master connected thereto by the serial-parallelconverter 220 and the FIFO 221.

This is the same relation as that of the second embodiment to the firstembodiment.

Other components and their operations in the fourth embodiment are thesame as those in the third embodiment, and the description thereof isomitted.

Note that in the description on the first to fourth embodiments,communication between the transmitter and the receiver is performedusing a four-phase handshake.

However, communication may be performed using a two-phase handshake.

In the description on the first to fourth embodiments, only two piecesof transmit data are burst transmitted between a transmitter and areceiver.

However, this is not limitative, and burst transmission of any number ofpieces of transmit data is possible.

In the description on the first to fourth embodiments, each of the datatransmission line d0 and the data transmission line d1 is a metal line.

However, the data transmission line d0 and the data transmission line d1may be replace by optical fibers for performing communication.

In this case, the encoder 100 is designed to have a light emitter thatoutputs a transmit symbol, which is a transmit data symbol, anidentification symbol or a non-transmit symbol, via optical fibers, andthe decoder 200 is designed to have a light receiver that receives atransmit symbol via optical fibers.

The light emitter also modulates the optical output with high frequencyin accordance with the transmit symbol, and the light receiver receiveshigh-frequency light modulated in accordance with the transmit symboland decodes the data.

In such a way as described above, high-speed serial data transfersystems according to the first to fourth embodiments can performcommunication under the reduced effects of electromagnetic waves and thelike from the outside when optical fibers are used for communication.

The high-speed serial data transfer systems according to the first tofourth embodiments can be formed on one silicon substrate to constitutea semiconductor device.

This enables a circuit in the semiconductor device formed on one siliconsubstrate to perform communication by a high-speed serial data transfersystem.

The high-speed serial data transfer systems according to the first tofourth embodiments can be formed an a plurality of different siliconsubstrates to constitute a hybrid semiconductor device.

This enables a circuit in one semiconductor device composed of differentsilicon substrates to perform communication by a high-speed serial datatransfer system.

A transmitter described as the transmitter 10 or 15 and a receiverdescribed as the receiver 20, 21, 25 or 26 may be ones each realized bythe dedicated hardware, and may also be realized by means of a memoryand a microprocessor.

In addition, this transmitter or receiver may be one realized by thededicated hardware, and may also include a memory and a CPU.

In the latter case, a program for implementing functions of thetransmitter or receiver is loaded onto the memory and executed, therebyimplementing the functions.

Hereinabove, the embodiments of this invention have been described indetail with reference to the accompanying drawings.

However, specific configurations are not limited to the embodiments, anddesigns and the like without departing from the scope of this inventionare included.

A high-speed serial data transfer system according to an embodiment ofthe invention is suited for communication devices connecting variousmanufacturing devices in a factory.

A high-speed serial data transfer system according to an embodiment ofthe invention is also suited for communication devices in semiconductordevices that operate at high speed and require low power consumption andthat can be bent because they are made of flexible materials such asfilms.

1. A transmitter for use in a variable-length serial burst data transfersystem having the transmitter and a receiver, the transmitter and thereceiver being connected by at least two data transmission lines and aburst start line, the transmitter comprising: a two-line encoder thatduring transmitting variable-length serial transmit data made up ofbinary digits, encodes the transmit data into transmit data symbols, thetransmit data symbols each associated with each piece of transmit datain advance, inserts an identification symbol for identifying thetransmit data symbols from one another between the transmit data symbolsresulting from encoding to encode the transmit data, and transmits theencoded transmit data via the two data transmission lines to thereceiver, and during non-transmit, transmits a non-transmit symbolrepresenting a non-transmit state via the two data transmission lines tothe receiver; and a burst start signal receiving portion that receives aburst start signal via the burst start line from the receiver, the burststart signal representing a start of burst transmission of thevariable-length serial transmit data; wherein the two-line encodertransmits the identification symbol to the receiver at the start of theburst transmission, and performs the burst transmission of thevariable-length serial transmit data in response to the burst requestsignal receiving portion receiving the burst start signal from thereceiver in accordance with the transmitted identification symbol.
 2. Atransmitter for use in a variable-length serial burst data transfersystem having the transmitter and a receiver, the transmitter and thereceiver being connected by at least two data transmission lines and aburst request line, the transmitter comprising: a burst request signalreceiving portion that receives a burst request signal via the burstrequest line from the receiver, the burst request signal being a signalrepresenting a request for burst transmission of variable-length serialtransmit data; and a two-line encoder that, responding to the burstrequest signal receiving portion receiving the burst request signal,during transmitting variable-length serial transmit data made up ofbinary digits, encodes the transmit data into transmit data symbols, thetransmit data symbols each associated with each piece of transmit datain advance, inserts an identification symbol for identifying thetransmit data symbols from one another between the transmit data symbolsresulting from encoding to encode the transmit data, and transmits theencoded transmit data via the two data transmission lines to thereceiver, and during non-transmit, transmits a non-transmit symbolrepresenting a non-transmit state via the two data transmission lines tothe receiver.
 3. A receiver for use in a variable-length serial burstdata transfer system having a transmitter and the receiver thetransmitter and the receiver being connected by at least two datatransmission lines and a burst start line, the receiver comprising: astorage that has received data stored therein and outputs a data emptysignal if being free of data stored; a two-line decoder that receivesvariable-length serial transmit data from the transmitter, thevariable-length serial transmit data being such that, duringtransmitting the variable-length serial transmit data made up of binarydigits, the transmit data is encoded into transmit data symbols, thetransmit data symbols each associated with each piece of transmit datain advance, an identification symbol for identifying the transmit datasymbols from one another is inserted between the transmit data symbolsresulting from encoding to encode the transmit data, and the encodedtransmit data is transmitted via the two data transmission lines to thereceiver, although during non-transmit, a non-transmit symbolrepresenting a non-transmit state is transmitted via the two datatransmission lines to the receiver, that outputs an identificationsymbol signal if the identification symbol included in the receivedvariable-length serial transmit data is decoded and outputs anon-transmit symbol signal if the non-transmit symbol included in thereceived variable-length serial transmit data is decoded, and thatdecodes the transmit data symbols resulting from encoding based on theidentification symbol included in the received variable-length serialtransmit data and stores the decoded transmit data symbols as thereceived data in the storage; a data invalid signal generator to whichthe non-transmit symbol signal and the identification symbol signal areinput from the two-line decoder, and that generates a data invalidsignal from an input of the non-transmit symbol signal to an input ofthe identification symbol signal, the data invalid signal representingthat the received data is free from being stored into the storage; aburst start signal generator to which the data invalid signal and thedata empty signal are input, and that generates a burst start signal ifboth the data invalid signal and the data empty signal are input, theburst start signal being a signal representing start of the bursttransmission of the variable-length serial transmit data; and a burststart signal transmitting portion that transmits to the transmitter theburst start signal generated by the burst start signal generator.
 4. Areceiver for use in a variable-length serial burst data transfer systemhaving a transmitter and the receiver, the transmitter and the receiverbeing connected by at least two data transmission lines and a burstrequest line, the receiver comprising: a storage that has received datastored therein and outputs a data empty signal if being free of datastored; a burst request signal transmitting portion that transmits aburst request signal via the burst request line to the transmitter theburst request signal being a signal that represents a request for bursttransmission of variable-length serial transmit data; a two-line decoderthat, responding to the transmitter receiving the burst request signal,receives variable-length serial transmit data from the transmitter, thevariable-length serial transmit data being such that, duringtransmitting the variable-length serial transmit data made up of binarydigits, the transmit data is encoded into transmit data symbols, thetransmit data symbols each associated with each piece of transmit datain advance, the transmit data symbols resulting from encoding having anidentification symbol for identifying the transmit data symbols from oneanother inserted therebetween to encode the transmit data, the encodedtransmit data transmitted via the two data transmission lines to thereceiver, although during non-transmit, a non-transmit symbolrepresenting a non-transmit state is transmitted via the two datatransmission lines to the receiver, that outputs an identificationsymbol signal if the identification symbol included in the receivedvariable-length serial transmit data is decoded and outputs anon-transmit symbol signal if the non-transmit symbol included in thereceived variable-length serial transmit data is decoded, and thatdecodes the transmit data symbols resulting from encoding based on theidentification symbol included in the received variable-length serialtransmit data and stores the decoded transmit data symbols as thereceived data in the storage; a data invalid signal generator to whichthe non-transmit symbol signal and the identification symbol signal areinput from the two-line decoder, and that generates a data invalidsignal from input of the non-transmit symbol signal to input of theidentification symbol signal, the data invalid signal representing thatthe received data is free from being stored into the storage; and aburst end signal generator to which the data invalid signal and the dataempty signal are input, and that generates and outputs a burst startsignal if both the data invalid signal and the data empty signal areinput, the burst end signal representing end of receiving thevariable-length serial transmit data.
 5. The receiver according to claim3, wherein: the two-line decoder outputs the received data to thestorage and transmits, during output of the received data to thestorage, a write signal to the storage to cause the received data to bestored into the storage; the receiver includes a strobe signal generatorto which the write signal output by the two-line decoder is input andthat outputs the input write signal to the storage; and the strobesignal generator masks the write signal, responding to the data invalidsignal being input from the data invalid signal generator.
 6. Thereceiver according to claim 3, wherein: the two-line decoder outputs thereceived data; and the transmitter includes a serial-parallel converterthat converts the received data output parallel by the two-line decoderby a predetermined number of bits and causes the received data convertedparallel to be stored into the storage.
 7. A transmitting method of atransmitter for use in a variable-length serial burst data transfersystem having the transmitter and a receiver the transmitter and thereceiver being connected by at least two data transmission lines and aburst start line, the transmitting method comprising: duringtransmitting variable-length serial transmit data made up of binarydigits, encoding the transmit data into transmit data symbols, thetransmit data symbols each associated with each piece of transmit datain advance, inserting an identification symbol for identifying thetransmit data symbols from one another between the transmit data symbolsresulting from encoding to encode the transmit data, and transmittingthe encoded transmit data via the two data transmission lines to thereceiver, and during non-transmit, transmitting a non-transmit symbolrepresenting a non-transmit state via the two data transmission lines tothe receiver; receiving a burst start signal via the burst start linefrom the receiver, the burst start signal representing start of bursttransmission of the variable-length serial transmit data; andtransmitting the identification symbol to the receiver at the start ofthe burst transmission, and performing the burst transmission of thevariable-length serial transmit data in response to the burst requestsignal receiving portion receiving the burst start signal from thereceiver in accordance with the transmitted identification symbol.
 8. Atransmitting method of a transmitter for use in a variable-length serialburst data transfer system having the transmitter and a receiver, thetransmitter and the receiver being connected by at least two datatransmission lines and a burst request line, the transmitting methodcomprising: receiving a burst request signal via the burst request linefrom the receiver, the burst request signal being a signal thatrepresents a request for burst transmission of variable-length serialtransmit data; and in response to the burst request signal receivingportion receiving the burst start signal, during transmittingvariable-length serial transmit data made up of binary digits, encodingthe transmit data into transmit data symbols, the transmit data symbolseach associated with each piece of transmit data in advance, insertingan identification symbol for identifying the transmit data symbols fromone another between the transmit data symbols resulting from encoding toencode the transmit data, and transmitting the encoded transmit data viathe two data transmission lines to the receiver, and duringnon-transmit, transmitting a non-transmit symbol representing anon-transmit state via the two data transmission lines to the receiver.9. A receiving method of a receiver for use in a variable-length serialburst data transfer system having a transmitter and the receiver, thetransmitter and the receiver being connected by at least two datatransmission lines and a burst start line, the receiving methodcomprising: receiving variable-length serial transmit data from thetransmitter, the variable-length serial transmit data being such that,during transmitting the variable-length serial transmit data made up ofbinary digits, the transmit data is encoded into transmit data symbols,the transmit data symbols each associated with each piece of transmitdata in advance, an identification symbol for identifying the transmitdata symbols from one another is inserted between the transmit datasymbols resulting from encoding to encode the transmit data, and theencoded transmit data transmitted via the two data transmission lines tothe receiver, although during non-transmit, a non-transmit symbolrepresenting a non-transmit state is transmitted via the two datatransmission lines to the receiver, outputting an identification symbolsignal if the identification symbol included in the receivedvariable-length serial transmit data is decoded and outputting anon-transmit symbol signal if the non-transmit symbol included in thereceived variable-length serial transmit data is decoded, and decodingthe transmit data symbols resulting from encoding based on theidentification symbol included in the received variable-length serialtransmit data and storing the decoded transmit data symbols as thereceived data in a storage; outputting a data empty signal if thestorage is free of data stored therein; receiving input of thenon-transmit symbol signal and the identification symbol signal, andgenerating a data invalid signal from input of the non-transmit symbolsignal to input of the identification symbol signal, the data invalidsignal representing that the received data is free from being storedinto the storage; receiving input of the data invalid signal and thedata empty signal, and generating a burst start signal if both the datainvalid signal and the data empty signal are input; and transmitting thegenerated burst start signal to the transmitter.
 10. A receiving methodof a receiver for use in a variable-length serial burst data transfersystem having a transmitter and the receiver, the transmitter and thereceiver being connected by at least two data transmission lines and aburst request line, the receiving method comprising: transmitting aburst request signal via the burst request line to the transmitter theburst request signal being a signal that represents a request for bursttransmission of variable-length serial transmit data; receiving, inresponse to the transmitter receiving the burst request signal,variable-length serial transmit data from the transmitter, thevariable-length serial transmit data being such that, duringtransmitting the variable-length serial transmit data made up of binarydigits, the transmit data is encoded into transmit data symbols, thetransmit data symbols each associated with each piece of transmit datain advance, an identification symbol for identifying the transmit datasymbols from one another is inserted between the transmit data symbolsresulting from encoding to encode the transmit data, and the encodedtransmit data is transmitted via the two data transmission lines to thereceiver, although during non-transmit, a non-transmit symbolrepresenting a non-transmit state is transmitted via the two datatransmission lines to the receiver, outputting an identification symbolsignal if the identification symbol included in the receivedvariable-length serial transmit data is decoded and outputting anon-transmit symbol signal if the non-transmit symbol included in thereceived variable-length serial transmit data is decoded, and decodingthe transmit data symbols resulting from encoding based on theidentification symbol included in the received variable-length serialtransmit data and storing the decoded transmit data symbols as thereceived data in the storage; outputting a data empty signal if thestorage being free of data stored therein; receiving input of thenon-transmit symbol signal and the identification symbol signal, andgenerating a data invalid signal from input of the non-transmit symbolsignal to input of the identification symbol signal, the data invalidsignal representing that the received data is free from being storedinto the storage; and receiving input of the data invalid signal thedata empty signal, and generating and outputting a burst start signal ifboth the data invalid signal and the data empty signal are input, theburst end signal representing end of receiving the variable-lengthserial transmit data.
 11. The receiving method according to claim 9,wherein the receiver outputs the received data to the storage andtransmits, during output of the received data to the storage, a writesignal to the storage to cause the received data to be stored into thestorage, and masks the write signal in response to the data invalidsignal being input.
 12. The receiving method according to claim 9,wherein the receiver converts the received data parallel by apredetermined number of bits and causes the received data convertedparallel to be stored into the storage.
 13. A variable-length serialburst data transfer system comprising a transmitter and a receiver, thetransmitter and the receiver being connected by at least two datatransmission lines and a burst start line, the transmitter including: atwo-line encoder that during transmitting variable-length serialtransmit data made up of binary digits, encodes the transmit data intotransmit data symbols, the transmit data symbols each associated witheach piece of transmit data in advance, inserts an identification symbolfor identifying the transmit data symbols from one another between thetransmit data symbols resulting from encoding to encode the transmitdata, and transmits the encoded transmit data via the two datatransmission lines to the receiver, and during non-transmit, transmits anon-transmit symbol representing a non-transmit state via the two datatransmission lines to the receiver; and a burst start signal receivingportion that receives a burst start signal via the burst start line fromthe receiver, the burst start signal being a signal that representsstart of burst transmission of the variable-length serial transmit data,wherein the two-line encoder transmits the identification symbol to thereceiver at the start of the burst transmission, and performs the bursttransmission of the variable-length serial transmit data in response tothe burst request signal receiving portion receiving the burst startsignal from the receiver in accordance with the transmittedidentification symbol; the receiver including: a storage that hasreceived data stored therein and outputs a data empty signal if beingfree of data stored; a two-line decoder that receives the encodedvariable-length serial transmit data from the transmitter, that outputsan identification symbol signal if the identification symbol included inthe received variable-length serial transmit data is decoded and outputsa non-transmit symbol signal if the non-transmit symbol included in thereceived variable-length serial transmit data is decoded, and thatdecodes the transmit data symbols resulting from encoding based on theidentification symbol included in the received variable-length serialtransmit data and stores the decoded transmit data symbols as thereceived data in the storage; a data invalid signal generator to whichthe non-transmit symbol signal and the identification symbol signal areinput from the two-line decoder, and that generates a data invalidsignal from input of the non-transmit symbol signal to input of theidentification symbol signal, the data invalid signal representing thatthe received data is free from being stored into the storage; a burststart signal generator to which the data invalid signal and the dataempty signal are input, and that generates a burst start signal if boththe data invalid signal and the data empty signal are input; and a burststart signal transmitting portion that transmits to the transmitter theburst start signal generated by the burst start signal generator.
 14. Avariable-length serial burst data transfer system comprising atransmitter and a receiver, the transmitter and the receiver beingconnected by at least two data transmission lines and a burst requestline, the receiver including: a burst request signal transmittingportion that transmits a burst request signal via the burst request lineto the transmitter the burst request signal being a signal thatrepresents a request for burst transmission of variable-length serialtransmit data; the transmitter including: a burst request signalreceiving portion that receives the burst request signal via the burstrequest line from the receiver; and a two-line encoder that, respondingto the burst request signal receiving portion receiving the burst startsignal, during transmitting variable-length serial transmit data made upof binary digits, encodes the transmit data into transmit data symbols,the transmit data symbols each associated with each piece of transmitdata in advance, inserts an identification symbol for identifying thetransmit data symbols from one another between the transmit data symbolsresulting from encoding to encode the transmit data, and transmits theencoded transmit data via the two data transmission lines to thereceiver, and during non-transmit, transmits a non-transmit symbolrepresenting a non-transmit state via the two data transmission lines tothe receiver; the receiver including: a storage that has received datastored therein and outputs a data empty signal if being free of datastored; a two-line decoder that receives the encoded variable-lengthserial transmit data from the transmitter, that outputs anidentification symbol signal if the identification symbol included inthe received variable-length serial transmit data is decoded and outputsa non-transmit symbol signal if the non-transmit symbol included in thereceived variable-length serial transmit data is decoded, and thatdecodes the transmit data symbols resulting from encoding based on theidentification symbol included in the received variable-length serialtransmit data and stores the decoded transmit data symbols as thereceived data in the storage; a data invalid signal generator to whichthe non-transmit symbol signal and the identification symbol signal areinput from the two-line decoder, and that generates a data invalidsignal from input of the non-transmit symbol signal to input of theidentification symbol signal, the data invalid signal representing thatthe received data is free from being stored into the storage; and aburst end signal generator to which the data invalid signal and the dataempty signal are input, and that generates and outputs a burst startsignal if both the data invalid signal and the data empty signal areinput, the burst end signal representing end of receiving thevariable-length serial transmit data.
 15. The variable-length serialburst data transfer system according to claim 13, wherein the datatransmission lines are each a metal line.
 16. The variable-length serialburst data transfer system according to claim 13, wherein: the datatransmission lines are each an optical fiber; the two-line encoderincludes a light emitter that outputs a transmit symbol via the opticalfiber, the transmit symbol being a transmit data symbol, anidentification symbol or a non-transmit symbol; and the two-line decoderincludes a light receiver that receives the transmit symbol via theoptical fiber.
 17. The variable-length serial burst data transfer systemaccording to claim 16, wherein: the light emitter modulates an opticaloutput with high frequency in accordance with the transmit symbol; andthe light receiver receives high-frequency light modulated in accordancewith the transmit symbol and decodes the data.
 18. A semiconductordevice having the variable-length serial burst data transfer systemaccording to claim 13 formed on one silicon substrate.
 19. A hybridsemiconductor device having the variable-length serial burst datatransfer system according to claim 13 formed on a plurality of differentsilicon substrates.